<template>
  <view id="_root" :class="(selectable ? '_select ' : '') + '_root'" :style="containerStyle">
    <slot v-if="!nodes[0]" />
    <!-- #ifndef APP-PLUS-NVUE -->
    <node
      v-else
      :childs="nodes"
      :opts="[lazyLoad, loadingImg, errorImg, showImgMenu, selectable]"
      name="span"
    />
    <!-- #endif -->
    <!-- #ifdef APP-PLUS-NVUE -->
    <web-view
      ref="web"
      src="/uni_modules/mp-html/static/app-plus/mp-html/local.html"
      :style="'margin-top:-2px;height:' + height + 'px'"
      @onPostMessage="_onMessage"
    />
    <!-- #endif -->
  </view>
</template>

<script>
/**
 * mp-html v2.5.0
 * @description 富文本组件
 * @tutorial https://github.com/jin-yufeng/mp-html
 * @property {String} container-style 容器的样式
 * @property {String} content 用于渲染的 html 字符串
 * @property {Boolean} copy-link 是否允许外部链接被点击时自动复制
 * @property {String} domain 主域名，用于拼接链接
 * @property {String} error-img 图片出错时的占位图链接
 * @property {Boolean} lazy-load 是否开启图片懒加载
 * @property {string} loading-img 图片加载过程中的占位图链接
 * @property {Boolean} pause-video 是否在播放一个视频时自动暂停其他视频
 * @property {Boolean} preview-img 是否允许图片被点击时自动预览
 * @property {Boolean} scroll-table 是否给每个表格添加一个滚动层使其能单独横向滚动
 * @property {Boolean | String} selectable 是否开启长按复制
 * @property {Boolean} set-title 是否将 title 标签的内容设置到页面标题
 * @property {Boolean} show-img-menu 是否允许图片被长按时显示菜单
 * @property {Object} tag-style 标签的默认样式
 * @property {Boolean | Number} use-anchor 是否使用锚点链接
 * @event {Function} load dom 结构加载完毕时触发
 * @event {Function} ready 所有图片加载完毕时触发
 * @event {Function} imgtap 图片被点击时触发
 * @event {Function} linktap 链接被点击时触发
 * @event {Function} play 音视频播放时触发
 * @event {Function} error 媒体加载出错时触发
 */
// #ifndef APP-PLUS-NVUE
import node from './node/node';
// #endif
import Parser from './parser';

const plugins = [];
// #ifdef APP-PLUS-NVUE
const dom = weex.requireModule('dom');
// #endif
export default {
  name: 'mp-html',
  data() {
    return {
      nodes: [],
      // #ifdef APP-PLUS-NVUE
      height: 3,
      // #endif
    };
  },
  props: {
    containerStyle: {
      type: String,
      default: '',
    },
    content: {
      type: String,
      default: '',
    },
    copyLink: {
      type: [Boolean, String],
      default: true,
    },
    domain: String,
    errorImg: {
      type: String,
      default: '',
    },
    lazyLoad: {
      type: [Boolean, String],
      default: false,
    },
    loadingImg: {
      type: String,
      default: '',
    },
    pauseVideo: {
      type: [Boolean, String],
      default: true,
    },
    previewImg: {
      type: [Boolean, String],
      default: true,
    },
    scrollTable: [Boolean, String],
    selectable: [Boolean, String],
    setTitle: {
      type: [Boolean, String],
      default: true,
    },
    showImgMenu: {
      type: [Boolean, String],
      default: true,
    },
    tagStyle: Object,
    useAnchor: [Boolean, Number],
  },
  // #ifdef VUE3
  emits: ['load', 'ready', 'imgtap', 'linktap', 'play', 'error'],
  // #endif
  // #ifndef APP-PLUS-NVUE
  components: {
    node,
  },
  // #endif
  watch: {
    content(content) {
      this.setContent(content);
    },
  },
  created() {
    this.plugins = [];
    for (let i = plugins.length; i--; ) {
      this.plugins.push(new plugins[i](this));
    }
  },
  mounted() {
    if (this.content && !this.nodes.length) {
      this.setContent(this.content);
    }
  },
  beforeUnmount() {
    this._hook('onDetached');
  },
  methods: {
    /**
     * @description 将锚点跳转的范围限定在一个 scroll-view 内
     * @param {Object} page scroll-view 所在页面的示例
     * @param {String} selector scroll-view 的选择器
     * @param {String} scrollTop scroll-view scroll-top 属性绑定的变量名
     */
    in(page, selector, scrollTop) {
      // #ifndef APP-PLUS-NVUE
      if (page && selector && scrollTop) {
        this._in = {
          page,
          selector,
          scrollTop,
        };
      }
      // #endif
    },

    /**
     * @description 锚点跳转
     * @param {String} id 要跳转的锚点 id
     * @param {Number} offset 跳转位置的偏移量
     * @returns {Promise}
     */
    navigateTo(id, offset) {
      return new Promise((resolve, reject) => {
        if (!this.useAnchor) {
          reject(Error('Anchor is disabled'));
          return;
        }
        offset = offset || parseInt(this.useAnchor) || 0;
        // #ifdef APP-PLUS-NVUE
        if (!id) {
          dom.scrollToElement(this.$refs.web, {
            offset,
          });
          resolve();
        } else {
          this._navigateTo = {
            resolve,
            reject,
            offset,
          };
          this.$refs.web.evalJs(
            `uni.postMessage({data:{action:"getOffset",offset:(document.getElementById(${id})||{}).offsetTop}})`,
          );
        }
        // #endif
        // #ifndef APP-PLUS-NVUE
        let deep = ' ';
        // #ifdef MP-WEIXIN || MP-QQ || MP-TOUTIAO
        deep = '>>>';
        // #endif
        const selector = uni
          .createSelectorQuery()
          // #ifndef MP-ALIPAY
          .in(this._in ? this._in.page : this)
          // #endif
          .select((this._in ? this._in.selector : '._root') + (id ? `${deep}#${id}` : ''))
          .boundingClientRect();
        if (this._in) {
          selector
            .select(this._in.selector)
            .scrollOffset()
            .select(this._in.selector)
            .boundingClientRect();
        } else {
          // 获取 scroll-view 的位置和滚动距离
          selector.selectViewport().scrollOffset(); // 获取窗口的滚动距离
        }
        selector.exec((res) => {
          if (!res[0]) {
            reject(Error('Label not found'));
            return;
          }
          const scrollTop = res[1].scrollTop + res[0].top - (res[2] ? res[2].top : 0) + offset;
          if (this._in) {
            // scroll-view 跳转
            this._in.page[this._in.scrollTop] = scrollTop;
          } else {
            // 页面跳转
            uni.pageScrollTo({
              scrollTop,
              duration: 300,
            });
          }
          resolve();
        });
        // #endif
      });
    },

    /**
     * @description 获取文本内容
     * @return {String}
     */
    getText(nodes) {
      let text = '';
      (function traversal(nodes) {
        for (let i = 0; i < nodes.length; i++) {
          const node = nodes[i];
          if (node.type === 'text') {
            text += node.text.replace(/&amp;/g, '&');
          } else if (node.name === 'br') {
            text += '\n';
          } else {
            // 块级标签前后加换行
            const isBlock =
              node.name === 'p' ||
              node.name === 'div' ||
              node.name === 'tr' ||
              node.name === 'li' ||
              (node.name[0] === 'h' && node.name[1] > '0' && node.name[1] < '7');
            if (isBlock && text && text[text.length - 1] !== '\n') {
              text += '\n';
            }
            // 递归获取子节点的文本
            if (node.children) {
              traversal(node.children);
            }
            if (isBlock && text[text.length - 1] !== '\n') {
              text += '\n';
            } else if (node.name === 'td' || node.name === 'th') {
              text += '\t';
            }
          }
        }
      })(nodes || this.nodes);
      return text;
    },

    /**
     * @description 获取内容大小和位置
     * @return {Promise}
     */
    getRect() {
      return new Promise((resolve, reject) => {
        uni
          .createSelectorQuery()
          // #ifndef MP-ALIPAY
          .in(this)
          // #endif
          .select('#_root')
          .boundingClientRect()
          .exec((res) => (res[0] ? resolve(res[0]) : reject(Error('Root label not found'))));
      });
    },

    /**
     * @description 暂停播放媒体
     */
    pauseMedia() {
      for (let i = (this._videos || []).length; i--; ) {
        this._videos[i].pause();
      }
      // #ifdef APP-PLUS
      const command =
        'for(var e=document.getElementsByTagName("video"),i=e.length;i--;)e[i].pause()';
      // #ifndef APP-PLUS-NVUE
      let page = this.$parent;
      while (!page.$scope) page = page.$parent;
      page.$scope.$getAppWebview().evalJS(command);
      // #endif
      // #ifdef APP-PLUS-NVUE
      this.$refs.web.evalJs(command);
      // #endif
      // #endif
    },

    /**
     * @description 设置媒体播放速率
     * @param {Number} rate 播放速率
     */
    setPlaybackRate(rate) {
      this.playbackRate = rate;
      for (let i = (this._videos || []).length; i--; ) {
        this._videos[i].playbackRate(rate);
      }
      // #ifdef APP-PLUS
      const command = `for(var e=document.getElementsByTagName("video"),i=e.length;i--;)e[i].playbackRate=${rate}`;
      // #ifndef APP-PLUS-NVUE
      let page = this.$parent;
      while (!page.$scope) page = page.$parent;
      page.$scope.$getAppWebview().evalJS(command);
      // #endif
      // #ifdef APP-PLUS-NVUE
      this.$refs.web.evalJs(command);
      // #endif
      // #endif
    },

    /**
     * @description 设置内容
     * @param {String} content html 内容
     * @param {Boolean} append 是否在尾部追加
     */
    setContent(content, append) {
      if (!append || !this.imgList) {
        this.imgList = [];
      }
      const nodes = new Parser(this).parse(content);
      // #ifdef APP-PLUS-NVUE
      if (this._ready) {
        this._set(nodes, append);
      }
      // #endif
      this.$set(this, 'nodes', append ? (this.nodes || []).concat(nodes) : nodes);

      // #ifndef APP-PLUS-NVUE
      this._videos = [];
      this.$nextTick(() => {
        this._hook('onLoad');
        this.$emit('load');
      });

      if (this.lazyLoad || this.imgList._unloadimgs < this.imgList.length / 2) {
        // 设置懒加载，每 350ms 获取高度，不变则认为加载完毕
        let height = 0;
        const callback = (rect) => {
          if (!rect || !rect.height) rect = {};
          // 350ms 总高度无变化就触发 ready 事件
          if (rect.height === height) {
            this.$emit('ready', rect);
          } else {
            height = rect.height;
            setTimeout(() => {
              this.getRect().then(callback).catch(callback);
            }, 350);
          }
        };
        this.getRect().then(callback).catch(callback);
      } else {
        // 未设置懒加载，等待所有图片加载完毕
        if (!this.imgList._unloadimgs) {
          this.getRect()
            .then((rect) => {
              this.$emit('ready', rect);
            })
            .catch(() => {
              this.$emit('ready', {});
            });
        }
      }
      // #endif
    },

    /**
     * @description 调用插件钩子函数
     */
    _hook(name) {
      for (let i = plugins.length; i--; ) {
        if (this.plugins[i][name]) {
          this.plugins[i][name]();
        }
      }
    },

    // #ifdef APP-PLUS-NVUE
    /**
     * @description 设置内容
     */
    _set(nodes, append) {
      this.$refs.web.evalJs(
        `setContent(${JSON.stringify(nodes).replace(/%22/g, '')},${JSON.stringify([
          this.containerStyle.replace(/(?:margin|padding)[^;]+/g, ''),
          this.errorImg,
          this.loadingImg,
          this.pauseVideo,
          this.scrollTable,
          this.selectable,
        ])},${append})`,
      );
    },

    /**
     * @description 接收到 web-view 消息
     */
    _onMessage(e) {
      const message = e.detail.data[0];
      switch (message.action) {
        // web-view 初始化完毕
        case 'onJSBridgeReady':
          this._ready = true;
          if (this.nodes) {
            this._set(this.nodes);
          }
          break;
        // 内容 dom 加载完毕
        case 'onLoad':
          this.height = message.height;
          this._hook('onLoad');
          this.$emit('load');
          break;
        // 所有图片加载完毕
        case 'onReady':
          this.getRect()
            .then((res) => {
              this.$emit('ready', res);
            })
            .catch(() => {
              this.$emit('ready', {});
            });
          break;
        // 总高度发生变化
        case 'onHeightChange':
          this.height = message.height;
          break;
        // 图片点击
        case 'onImgTap':
          this.$emit('imgtap', message.attrs);
          if (this.previewImg) {
            uni.previewImage({
              current: parseInt(message.attrs.i, 10),
              urls: this.imgList,
            });
          }
          break;
        // 链接点击
        case 'onLinkTap': {
          const { href } = message.attrs;
          this.$emit('linktap', message.attrs);
          if (href) {
            // 锚点跳转
            if (href[0] === '#') {
              if (this.useAnchor) {
                dom.scrollToElement(this.$refs.web, {
                  offset: message.offset,
                });
              }
            } else if (href.includes('://')) {
              // 打开外链
              if (this.copyLink) {
                plus.runtime.openWeb(href);
              }
            } else {
              uni.navigateTo({
                url: href,
                fail() {
                  uni.switchTab({
                    url: href,
                  });
                },
              });
            }
          }
          break;
        }
        case 'onPlay':
          this.$emit('play');
          break;
        // 获取到锚点的偏移量
        case 'getOffset':
          if (typeof message.offset === 'number') {
            dom.scrollToElement(this.$refs.web, {
              offset: message.offset + this._navigateTo.offset,
            });
            this._navigateTo.resolve();
          } else {
            this._navigateTo.reject(Error('Label not found'));
          }
          break;
        // 点击
        case 'onClick':
          this.$emit('tap');
          this.$emit('click');
          break;
        // 出错
        case 'onError':
          this.$emit('error', {
            source: message.source,
            attrs: message.attrs,
          });
      }
    },
    // #endif
  },
};
</script>

<style>
/* #ifndef APP-PLUS-NVUE */
/* 根节点样式 */
._root {
  padding: 1px 0;
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
}

/* 长按复制 */
._select {
  user-select: text;
}
/* #endif */
</style>
